Structural characterization of the ternary compound Cu3TaSe4

The Cu3TaSe4 compound crystallizes in the cubic P4¯3m (No. 215) space group, Z = 1, with a = 5.6600(1) Å, V = 181.32(1) Å3. Its structure was refined from X-ray powder diffraction data using the Rietveld method. The refinement of 21 instrumental and structural variables led to Rp = 12.2%, Rwp = 14.7%, Rexp = 8.0%, RB = 14.5% and S = 1.8, for 4501 step intensities and 33 independent reflections. This compound is isostructural with the sulvanite mineral and is characterized for a three-dimensional arrangement of CuSe4 and TaSe4 tetrahedra connected by common edges, and the CuSe4 tetrahedra sharing vertexes among them.